This section provides background information related to the present disclosure that is not necessarily prior art. Example embodiments will now be described more fully with reference to the accompanying drawings. As indicated above, processes for preparing floor underlayment, such as medium density floor underlayment, are known to those skilled in this art.
Textile pads are widely used in flooring applications. A pad is desirable when wood flooring is applied over sub flooring. These pads used in flooring applications serve multiple purposes. They may absorb impact, such as from persons walking on the flooring. They may provide sound deadening, and may provide insulating properties against heat transfer. Pads also may accommodate roughness, unevenness, or other flaws in the sub flooring, and may provide a barrier against moisture and dirt. Finally, pads may lessen impact stresses on the flooring to lengthen the life of the flooring and make the flooring appear to be more durable and of a higher quality. Traditionally, these pads are formed when fibers of various sizes and materials are mixed and bound together. The binding can occur using know techniques such as needling or by the use of meltable binder fibers such as polypropylene. These techniques, while functional have several disadvantages which lead to slow throughput, high energy and cost, and environmental emissions.
In the construction of buildings having concrete subfloors, it is known to install a thin layer of integral polyethylene foam having a separate vapor barrier layered thereon. The concrete subflooring, followed by a layer of polyethylene foam sheet on the thin integral polyethylene vapor barrier, and vice versa, and then to install wood flooring on top of the polyethylene foam sheet layer. None of the layers or flooring are adhered to any of the other layers or flooring. The polyethylene foam sheet takes out small irregularities in the top surface of the concrete. The polyethylene foam sheet also provides some sound reduction. Slight cushioning is provided by the polyethylene foam sheet to alleviate the problems suffered by persons walking and standing on such floors. These foam insulative pads are unfortunately expensive to make and if made of a bi-material construction not recyclable.